Adam Clarke's Commentary on the Bible

Verse 6 (1 Timothy 6:6)

But godliness with contentment is great gain - The word godliness, ευσεβεια , here, and in several other places of this epistle, signifies the true religion, Christianity; and the word contentment, αυταρκεια , signifies a competency, a sufficiency; that measure or portion of secular things which is necessary for the support of life, while the great work of regeneration is carrying on in the soul. Not what this or the other person may deem a competency, but what is necessary for the mere purposes of life in reference to another world; food, raiment, and lodging. See 1 Timothy 6:7 . So, if a man have the life of God in his soul, and just a sufficiency of food and raiment to preserve and not burden life, he has what God calls great gain, an abundant portion.

It requires but little of this world's goods to satisfy a man who feels himself to be a citizen of another country, and knows that this is not his rest.

- Adam Clarke's Commentary on the Bible